Related Studies

The Harmonized Cognitive Assessment Protocol (HCAP) Network is a group of researchers working together to support harmonization of international studies using the Harmonized Cognitive Assessment Protocol (HCAP). HCAP was designed by the Health and Retirement Study (HRS) team in consultation with several of its international sister studies to provide a flexible but comparable instrument for measuring cognitive function among older adults around the world. The ultimate goal of the HCAP Network is to develop international data resources for the study of Alzheimer’s Disease and Alzheimer’s Disease Related Dementias (AD/ADRD). These data resources will expand research opportunities to exploit cross-country variation in key life-course factors that likely affect cognitive function and the risk for AD/ADRD, such as educational attainment, wealth, retirement policies, diet, and the prevalence and treatment of cardiovascular risk factors. At the same time, cross-country variations also raise unique challenges for maintaining the harmonization of tests and measures necessary for good comparative research. The HCAP Network addresses these challenges through a range of activities.

Studies In the HCAP Network

HRS-HCAPHealth and Retirement Study
HRS-HCAP is part of the HCAP Network, an ongoing international research collaboration funded by the National Institute on Aging to measure and understand dementia risk within ongoing longitudinal studies of aging around the world that have aimed to harmonize methods and content to facilitate cross-national comparisons.

CHARLSChina Health and Retirement Longitudinal Study
The China Health and Retirement Longitudinal Study (CHARLS) aims to collect a high quality nationally representative sample of Chinese residents ages 45 and older to serve the needs of scientific research on the elderly. The baseline national wave of CHARLS is being fielded in 2011and includes about 10,000 households and 17,500 individuals in 150 counties/districts and 450 villages/resident committees. The individuals will be followed up every two years. All data will be made public one year after the end of data collection.

CADASCaribbean American Dementia and Aging Study
The Caribbean American Dementia and Aging Study(CADAS) seeks to expand understanding of the lifecourse determinants and consequences of Alzheimer’s Disease and related dementias (AD/ADRD) in Caribbean-origin populations. We are collecting new nationally representative household survey data among adults ages 65+ in Puerto Rico (n=1500) and Dominican Republic (n=1500) to estimate the prevalence of dementia and to capture the variation in lifecourse exposures to AD/ADRD risk factors, as well as family and societal effects of dementia. We build on previous research by the 10/66 Dementia Research Group that indicates a remarkably high dementia prevalence of 10-12% among metro-dwelling adults aged 65+ in Puerto Rico, Dominican Republic and Cuba, whose similar histories but richly varying societal structures over the past century offer great promise for better understanding AD/ADRD. These Hispanic Caribbean sites are also the origin of the vast majority of Caribbean immigrants to the U.S., and we will also compare experiences in sending countries with experiences among U.S. immigrants. Our surveys are designed for cross-harmonization with both past 10/66 surveys as well as the global network of recent surveys using the Harmonized Cognitive Assessment Protocol, including the U.S. Health and Retirement Study.

ELSA-HCAPEnglish Longitudinal Study of Ageing (ELSA): Healthy Cognitive Ageing Project
The Healthy Cognitive Ageing Project (HCAP) aims to investigate dementia risk using a harmonised cognitive assessment protocol, as part of an international research collaboration funded by the National Institute on Aging (NIA). The HCAP cognitive assessments were carried out in face-to-face interviews in participants’ homes or institution in which they live, by a trained survey interviewer using CAPI methods. The study involved 1,274 ELSA participants aged 65 and older, of whom 676 participants were sampled with normal cognition, 419 with probable Mild Cognitive Impairment (MCI) and 179 with dementia. A total of 1,137 family/informant interviews (618 normal cognition, 365 probable MCI and 154 with dementia) were completed. The HCAP has been designed to leverage the Health and Retirement Study (HRS) international network of studies to produce comparable data on cognition and research diagnoses of dementia and mild cognitive impairment, to support joint epidemiological analysis of the aetiology and impact of cognitive decline and to make comparable national estimates of the dementia prevalence around the world. The protocol was designed to harmonise well with prior studies, including the 10/66 studies, the Rush University Memory and Aging Project and the HRS dementia study known as ADAMS. Versions of HCAP will also be conducted in the US, Mexico, India, China, and South Africa.

HAALSI Dementia StudyHealth and Aging in Africa: Cognitive Function, Alzheimer’s Disease and Related Disorders in the HAALSI Cohort
The Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa’s Cognitive Function, Alzheimer’s Disease and Related Disorders in the HAALSI Cohort project is an NIH-funded project furthers research conducted by the HAALSI team on the social and biological risk factors for Alzheimer’s disease and related dementias (ADRD) in an aging population in rural South Africa. The HAALSI Dementia Study will follow a cohort of 600 participants through two additional waves of dementia diagnostic evaluation—including an enriched cognitive battery, informant interviews, and neurological examinations. We will also recruit additional participants at risk for dementia from the parent HAALSI study, ultimately leading to a more accurate understanding of ADRD prevalence in the larger cohort. Magnetic resonance imaging (MRI) and venous blood draws will be conducted to better characterize structural brain aging and genetic markers of ADRD in this unique population.

TILDAIrish Longitudinal Study on Ageing
The Irish LongituDinal Study on Ageing (TILDA) is the most detailed study on ageing ever undertaken in Ireland. This ground-breaking study looks at the health, lifestyles and financial situation of 8,504 people as they grow older, and sees how their circumstances change over a 10 year period. TILDA collects information on all aspects of health, economic and social circumstances from people aged 50 and over in a series of data collection waves once every two years. TILDA is unique amongst longitudinal studies in the breadth of physical, mental health and cognitive measures collected. The study is being carried out by Trinity College Dublin in collaboration with an inter-disciplinary panel of experts in various fields of ageing.

LASI-DADLongitudinal Aging Study in India: Diagnostic Assessment of Dementia
Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD) is an in-depth study of late-life cognition and dementia, drawing a subsample of the Longitudinal Aging Study in India (LASI). LASI is a nationally representative survey of the health, economic, and social well-being of the Indian population aged 45 and older. Its large sample of 72,000+ adults represents not only the country as a whole, but also each state. We recruited a sub-sample of 4,000+ LASI respondents aged 60 or older from 18 states and union territories across the country, administered in-depth cognitive tests, and interviewed a family member or friend, whom study participants nominated as informants. We carefully selected a set of cognitive tests to enable international comparisons with other dementia studies around the world, including the U.S. HRS-HCAP (Harmonized Cognitive Assessment Protocol) and prior studies in India. LASI-DAD also collected rich data on risk factors through geriatric assessments (e.g., anthropometry, blood pressure measurements, hearing tests, venous blood assays), as well as nutritional and environmental assessments (exposure to air pollution and neighborhood conditions). For a sub-sample, brain imaging data are collected using the Alzheimer’s Disease Neuroimaging Initiative (ADNI)-3 protocol.

Mex-CogMexican Health and Aging Study: Cognitive Aging Ancillary Study
The Cognitive Aging Ancillary Study (Mex-Cog) was designed to complete an in-depth cognitive assessment in a subsample of the Mexican Health and Aging Study (MHAS) using a harmonized cognitive assessment protocol (HCAP). Adapted versions of the HCAP have been used to assess cognition in other subsamples within ongoing population-based longitudinal studies of aging around the world. A subsample of 2,265 respondents were selected for the MHAS Cognitive Aging Ancillary Study (Mex-Cog), fielded in 2016. The protocol included a comprehensive cognitive assessment and an interview with a knowledgeable informant, as well as anthropometric tests. This was part of the harmonized cognitive assessment protocol (HCAP) coordinated by the HRS, to evaluate the prevalence of dementia among older population in several countries.

NICOLANorthern Ireland Cohort for the Longitudinal Study of Ageing
The NICOLA project is thus the first large scale longitudinal study of ageing in Northern Ireland. It will help us gain a better understanding of the factors that affect social and health outcomes in the older Northern Ireland population. Over time, it will inform new prevention strategies, new interventions, new models of health and social care delivery, and more. It has been designed to maximize comparability with other well-established international longitudinal studies, in particular the Health and Retirement Survey (HRS) in the United States, ELSA, and TILDA, thereby facilitating cross-country comparisons. The study has recruited 8,500 people from across Northern Ireland to provide a true representation of the Northern Ireland population.  Our aim is to monitor these individuals and examine how their health, lifestyle, financial circumstances and overall wellbeing changes over the next 10 years. Led by the Centre for Public Health at Queen’s University Belfast (QUB), NICOLA benefits from extensive input from a wide range of experts.

SHARE-HCAPSurvey of Health, Aging and Retirement in Europe
The general aim of SHARE-HCAP is to exploit the international variation of health and life circumstances in Continental Europe to identify which interactions of bio-medical and socio-economic conditions over the life course affect cognition in later life. The project will administer in-depth measurement of cognition according to the Harmonized Cognitive Assessment Protocol (HCAP) that has been developed for the HRS-style ageing surveys. Using these data, the project will estimate prevalence rates of mild and severe cognitive impairment in the SHARE countries; compare these with HRS and other participants in the HCAP studies; and exploit the international variation of the SHARE plus SHARE-HCAP data in order to identify which interactions of biomedical and socioeconomic conditions over the life course affect cognition later in life. The project will be implemented in five SHARE countries (Denmark, Czech Republic, Germany, France, Italy) in a stratified study sample of 2,500 SHARE panel respondents. The start of the fieldwork is planned by early 2022.